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Shielding and activation of a viral membrane fusion protein.
- Source :
-
Nature communications [Nat Commun] 2018 Jan 24; Vol. 9 (1), pp. 349. Date of Electronic Publication: 2018 Jan 24. - Publication Year :
- 2018
-
Abstract
- Entry of enveloped viruses relies on insertion of hydrophobic residues of the viral fusion protein into the host cell membrane. However, the intermediate conformations during fusion remain unknown. Here, we address the fusion mechanism of Rift Valley fever virus. We determine the crystal structure of the Gn glycoprotein and fit it with the Gc fusion protein into cryo-electron microscopy reconstructions of the virion. Our analysis reveals how the Gn shields the hydrophobic fusion loops of the Gc, preventing premature fusion. Electron cryotomography of virions interacting with membranes under acidic conditions reveals how the fusogenic Gc is activated upon removal of the Gn shield. Repositioning of the Gn allows extension of Gc and insertion of fusion loops in the outer leaflet of the target membrane. These data show early structural transitions that enveloped viruses undergo during host cell entry and indicate that analogous shielding mechanisms are utilized across diverse virus families.
- Subjects :
- Cryoelectron Microscopy
Crystallography, X-Ray
HEK293 Cells
Humans
Hydrophobic and Hydrophilic Interactions
Multiprotein Complexes chemistry
Multiprotein Complexes metabolism
Protein Folding
Rift Valley fever virus physiology
Viral Fusion Proteins genetics
Virion metabolism
Viral Fusion Proteins chemistry
Viral Fusion Proteins metabolism
Virion chemistry
Virus Internalization
Subjects
Details
- Language :
- English
- ISSN :
- 2041-1723
- Volume :
- 9
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature communications
- Publication Type :
- Academic Journal
- Accession number :
- 29367607
- Full Text :
- https://doi.org/10.1038/s41467-017-02789-2